The catastrophe that killed the dinosaurs created a global hothouse for 100,000 years, study says

Thursday, May 3, 2018

By Joel Achenbach, The Washington Post, May 24

On a very bad day 66 million years ago, a mountain-sized object from space slammed into the Earth, initiating a cascade of calamities that eradicated three-fourths of the species on the planet, including the non-avian dinosaurs. The buried remnants of the 125-mile-wide crater have been identified on the Yucatan Peninsula and in the Gulf of Mexico. Scientists have long theorized that an initial pulse of heat was followed by a devastating global winter. After that, as carbon dioxide in the atmosphere surged, the planet became a hothouse.

A new study published Thursday in the journal Science has produced hard data to support that global warming hypothesis, and it may have unnerving implications for the world we live in today. The effects of the Chicxulub impact, named for a Yucatan town, produced 5 degrees Celsius (9 degrees Fahrenheit) average warming in a subtropical sea, and this heating persisted for 100,000 years, the researchers concluded.

“This is crocodiles at the poles and large areas of the tropics uninhabitable on land,” explained lead author Ken MacLeod, a University of Missouri paleontologist.

The study suggests that even a relatively brief pulse of CO2 can have a lingering effect. That's relevant today given many countries' massive greenhouse-gas emissions, which are creating a spike in atmospheric carbon dioxide and associated global warming.